Vanderbilt University

NSF Awards · FY 2024 · 2024-10

An exit ticket is a recommended and widely used way to end a lesson. A typical exit ticket format in mathematics lessons is for students to solve a few problems related to the day's lesson and turn it in when they exit the classroom. The most common purpose of exit tickets is to provide formative feedback to teachers about whether students have met the objectives of a given lesson. However, the psychology of learning literature suggests that there is an untapped potential for exit tickets to also benefit student's learning directly. This project explores two potential enhancements to exit tickets, with the goal of improving high-school student's mathematics knowledge and ability to regulate their own learning processes. These enhancements can be implemented easily by teachers in the context of exit tickets to support students self-reflection. This project will explore the impact of enhancements for supporting students in (1) determining how well they know material and (2) evaluating their strategy use and answers. These enhancements could benefit student's mathematics performance on content tests and improve the quality of high-school mathematics instruction. The findings could generalize to a wide range of grades and domains and to other formative assessment types. Dissemination efforts will include sharing the results with practitioners, district administrators, and digital learning creators to increase the use of enhanced exit tickets if they are successful. The project team will work with Integrated Mathematics I teachers to add enhancements to exit tickets for one curriculum unit and investigate whether and how the enhancements improve student outcomes. At least 680 students in a metropolitan school district that serves racially and economically diverse students will participate. The project uses a pretest-intervention-posttest design, with students randomly assigned to one of two conditions within their classroom: 1) enhanced exit tickets or 2) typical exit tickets. At pretest and posttest, students will complete measures of targeted self-regulated learning components (confidence calibration, metacognitive evaluation, mathematics self-efficacy, and mastery-approach goal orientation) as well as an assessment of mathematics performance. Using hierarchical linear models, analyses will investigate whether the enhanced exit tickets show more positive effects on student outcomes than typical exit tickets. Teacher interviews will explore whether the exit tickets were feasible for teachers to regularly implement and informed their instructional practices. Student interviews will explore student's perceptions of the exit ticket enhancements. The research will expand existing theories of self-regulated learning by evaluating whether specific supports for self-reflection can each benefit multiple self-regulated learning outcomes as well as mathematics performance. The proposed studies will also reveal ways that this formative assessment device can be adapted to enhance student's self-regulated learning and content knowledge. These enhancements could lead to exit tickets serving as a formative assessment of student's self-regulated learning practices. This project is funded by the Discovery Research preK-12 program (DRK-12) that seeks to significantly enhance the learning and teaching of science, technology, engineering, and mathematics (STEM) by preK-12 students and teachers, through research and development of innovative resources, models, and tools. Projects in the DRK-12 program build on fundamental research in STEM education and prior research and development efforts that provide theoretical and empirical justification for proposed projects. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2025 · 2024-09

PROJECT SUMMARY This project aims to computationally assess the impact aging-related oxidative stress has on the human proteome via a novel deep learning methodology. As a person ages, oxidative damage accumulates within their cells through exposure to both endogenous and exogenous sources. While the correlation between oxidative damage and aging is well-known, the specific mechanisms through which oxidation leads to aging-related ailments is complex and not well understood. Therefore, there exists a need for datasets which comprehensively enumerate how the human proteome is modified under oxidative stress. Although there exist mass spectroscopic methods for detecting these modifications, they are highly cost and labor intensive to do on a proteome-wide scale; computational prediction methods can help generate these datasets efficiently and complement existing datasets. However, oxidation modification prediction faces its own challenges due to the relative lack of known modification sites for training models when compared to other types of post-translational modifications. Therefore, I propose to build predictors for this problem by first constructing a deep learning- based atomic protein structure embedding method using a graph transformer autoencoder architecture. This autoencoder will be trained to embed and recover the atomic features of a set of high-resolution protein structures and high-confidence AlphaFold2 models. The resulting embedding model will then be benchmarked against state-of-the-art tools in a few protein function prediction tasks to ensure the information captured within the embedding is useful for biochemical analysis. This embedding approach not only allows the downstream classifiers to use the rich information contained within the training set of the embedding model, but also demonstrates the potential to extend to other biomolecules outside of the protein training set. Once the embedding procedure has been developed, a set of classifiers will be trained based on the deep learning-based embeddings to predict the likelihood of oxidation-related modifications occurring at a given protein residue. These classifiers will then be applied to the entire human proteome, resulting in a comprehensive proteome- wide prediction dataset of oxidation modification sites. This dataset will then be analyzed for functional pathway enrichment and individual proteins of interest. The most salient of these predicted modifications will be confirmed via mass spectroscopy. Finally, as an application to aging-related disease, proteins implicated in the progression of Alzheimer’s disease will be investigated in depth. Through successful completion of this research, a versatile deep learning-based method for encoding protein geometry at atomic resolution will be created, and novel functional insights and therapeutic targets will be derived from a comprehensive dataset of the predicted oxidation modification of the human proteome.

NIH Research Projects · FY 2025 · 2024-09

The older (aged 50 or above) never-married (ONM) population has been growing rapidly and comprises individuals who vary in age, sex, educational background, economic status, and reasons for being single. Its growth poses pressing and complex challenges for aging, age-related diseases, health care, and long-term care. However, this population remains severely understudied. Their health remains a contested issue, with social networks central to the discussion. Two conceptual models (deficits versus resilience) have competing predictions. Although many studies document ONM adults’ health and network disadvantages, they often overlook key factors such as age, sex, educational background, economic status, and reasons for being single. The features and impacts of social networks within ONM adults are complex and require rigorous investigation. The little research on ONM adults is largely due to data limitations. Population-based surveys of older adults have small never-married sample sizes and/or limited measurement of social networks and single life, leading to incomplete network mapping, insufficient network theory testing, underpowered analyses, and a lack of attention to these key factors among ONM adults. To address these critical gaps, we propose a pilot study to demonstrate the feasibility of conducting nationally representative surveys on ONM adults. In partnership with Gallup, we will collect the first-ever nationally representative pilot survey data on ONM adults, focusing on the role of social networks in the etiology of health risk behaviors and health and the intra- and interpersonal mechanisms underlying the role of social networks, with attention to these key factors.

NIH Research Projects · FY 2025 · 2024-09

Modified Project Summary/Abstract Section Suicidal ideation (SI) is a strong predictor of suicide–the second leading cause of death for adolescents and a national public health priority–and occurs in a significant proportion of adolescents. Adolescents who are at an elevated risk for mental health disparities, such as sexual minority (SM) youth, show even greater prevalence of SI. Considering these high rates of SI in SM youth, it is critical to identify intervention targets as a first step in designing efficacious treatments to prevent death by suicide. One such intervention target may be low reward responsiveness, which is associated with SI above and beyond the influence of depression or anhedonia and tends to be blunted in SM youth, particularly within social contexts. Despite this association, no research has evaluated low social reward responsiveness as a mechanism of SI in SM youth. Further, no research has evaluated potential moderators, such as interpersonal stress, on the association among low social reward responsiveness and SI in SM youth. This is critical, as SM youth are at an increased risk of experiencing interpersonal stress and mental health disparities due in part to experiences of stigma, prejudice, and discrimination. The proposed project will address these gaps by testing a novel mechanism linking SM identity to increased SI risk and examining the moderating role of interpersonal stress, leveraging an innovative approach with a large high-risk sample of adolescents. The proposed study will test these pathways in a sample of 210 adolescents (aged 13-17) following discharge from acute psychiatric treatment for self-injurious thoughts and behaviors (SITBs). Based on prior research and our own work with adolescents in partial and inpatient treatment, we expect that ~50% of participants will hold an SM identity. Participants will undergo an electroencephalogram (EEG), answer self-report measures, and complete semi-structured interviews to characterize SITB history. Acute interpersonal stressors, social support, and suicidal behavior will be assessed using a brief daily survey for 90 days following discharge, with self-report and interview measures obtained at 3-month follow-up. Through the longitudinal collection of these data, the present study aims to (1) Examine patterns of social reward responsiveness at the neural level in SM youth compared to heterosexual youth in acute psychiatric treatment for SITBs; (2) Evaluate low social reward responsiveness as a mechanism underlying increased SI severity in SM youth after hospital discharge; and (3) Test interpersonal stress as a moderator in the relation between SM status, low social reward responsiveness, and SI. Through support granted by this fellowship, the applicant will have the opportunity to develop advanced EEG skills, gain a deeper understanding of risk for psychopathology and SITBs in SM youth, acquire proficiency in longitudinal data analysis, and receive individualized mentorship in grant writing and enhancement of professional skills. Funding from this fellowship will provide the applicant with the necessary skills for a successful career as a clinical scientist.

NIH Research Projects · FY 2025 · 2024-09

Project Summary This proposal requests support for investigating the structure and enzymology of glucose-6-phosphatase catalytic subunit 1 (G6PC1), an integral membrane protein of the phosphatidic acid phosphatase type 2 (PAP2) superfamily expressed in the ER that catalyzes glucose production in the liver. Unregulated G6PC1 activity contributes to diabetes pathology by driving increases in hepatic glucose production and fasting blood glucose. In contrast, mutations in G6PC1 that impair activity cause glycogen storage disease type 1a (GSD type 1a), which is characterized primarily by severe hypoglycemia. Despite its physiological relevance to glucose metabolism, the structural basis of catalysis as well as the impairment caused by disease-linked mutations is poorly understood. This application outlines an experimental plan encompassed within three specific aims that integrates complementary biophysical and computational techniques to study the mechanistic structural biology of mouse G6PC1 (mG6PC1), a stable G6PC1 ortholog, in unprecedented detail. The research plan is facilitated by published methodological advancements developed in the PI’s laboratory that support purification of functional mG6PC1 from Sf9 cell membranes. The scientific approach capitalizes on preliminary 3D models predicted within the AlphaFold2 (AF2) computational framework as templates for experimental design. The cornerstone of this proposal is the application of double electron electron resonance (DEER) spectroscopy between nitroxide spin labels introduced into the mG6PC1 sequence to establish the veracity of computational models, obtain restraints for structural refinement and to describe the conformational dynamics of the catalytic cycle. The relative stability of these intermediates will be assessed in the background of mutants known to cause GSD type 1a. Informed by the spectroscopic analysis, cryogenic electron microscopy single particle analysis will be used to build high resolution models of stable catalytic intermediates. The experimental approach is grounded in the expertise of the PI and the team of established collaborators in the molecular biology of G6PC1 and the biophysical analysis of membrane proteins employing the described toolkit. A working mechanistic model has been derived from pilot spectroscopic studies indicating that mG6PC1 operates by a substrate-dependent conformational equilibrium between “resting” and “active” states mediated by relative rearrangement of a unique ancillary motif of transmembrane helices attached to the conserved PAP2 domain. Molecular dynamics simulations in conjunction with a robust in vitro platform for screening expression and activity have uncovered multiple modes of catalytic inhibition induced by GSD type 1a variants found in the active site. The research strategy will extend these findings beyond the active site into other hot spots for missense mutations found in the supporting loops and transmembrane helices. Interpreted within the context of high-resolution molecular models, the results of this work will uncover the orchestrated pattern of conformational changes underpinning catalysis as well as the thermodynamic and kinetic basis of inhibition induced by disease-linked mutations.

NIH Research Projects · FY 2025 · 2024-09

Adolescents & young adults (AYA) accounted for >400,000 new HIV infections in 2021 worldwide. Heavy alcohol use is a prevalent and strong modifiable risk factor for HIV transmission risk behavior. Studies from in high-income countries show that AYA often misperceive peer norms around health and health risk behavior and that these misperceptions increase risk behavior and impede health behavior. While these perceptions are modifiable risk factors, few studies of AYA in high HIV-burden settings describe how misperceptions of peer norms drive alcohol use and HIV/STI transmission risk and prevention behavior and associated health outcomes nor address how to change misperceived norms. The central hypotheses of this application are that AYA frequently misperceive peer norms about alcohol consumption and HIV/STI prevention; that these misperceptions affect their own propensities to engage in HIV/STI transmission risk behavior; and that perceived norms are malleable when AYA receive information about actual peer norms that conflicts with personal perceptions and behavior. These hypotheses have been formulated based on preliminary data showing that AYA in high-burden settings misperceive norms about alcohol use and HIV/STI transmission risk behavior, a finding that is consistent with other preliminary data demonstrating similar phenomena among adults. The preliminary data are also consistent with published trials from the US showing that AYA misperceptions can be altered through “personalized normative feedback” and other norms correction interventions wherein they are provided with correct information about actual norms. The team has engaged local leaders & educators in a high-burden setting to propose a population-based cohort study, in which they will embed a randomized controlled trial, of AYA in 3 secondary schools to achieve three specific aims: 1) Use qualitative methods to explore perceived norms around alcohol, HIV/STI transmission risk behavior, and HIV/STI prevention among AYA; 2) Estimate the causal effects of perceived norms around alcohol use and HIV/STI transmission risk behavior on HIV/STI prevention among AYA; and, 3) Conduct a mixed-methods, randomized controlled trial to test the preliminary efficacy and mediating mechanism of a personalized normative feedback intervention on behavioral intentions, heavy alcohol use, and HIV/STI prevention among AYA. The key innovation is that this study will be the first to rigorously estimate the causal influence of perceived peer norms around alcohol and HIV/STI transmission risk behavior on HIV/STI prevention among AYA in high-burden settings. The study will have significant public health impact by laying the foundation for strategies to focus on changing misperceived norms to influence HIV/STI prevention uptake among AYA.

NIH Research Projects · FY 2025 · 2024-09

Project Summary Abstract Children’s reading and math skills are critical to their future educational outcomes, career readiness, and overall health and well-being (e.g., ACT, 2020; Cain & Oakhill, 2006; DeWalt et al., 2004; Geary, 2011; Heilmann, 2020; Krajewski & Schneider, 2009; Ritchie & Bates, 2013), yet many children struggle with math and learning to read (National Center for Education Statistics, 2020). Individuals who struggle with math or learning to read often display weaknesses in executive function (EF) skills on behavioral measures (Peng & Fuchs, 2014), which could underline one of the fundamental bases of their deficits in reading and math. Conversely, individuals who struggle with reading or math may need to recruit additional EF skills to compensate for their poor reading and math problem-solving to meet task demands (Martinez-Lincoln et al., in review). By understanding the association between EF and domain-specific academic skills, we will have greater insight into the development of reading and math, and how EF can hinder or facilitate academic growth. This proposal aims to examine the recruitment of domain-general vs. domain-specific EF (Aim 1) and the connectivity for domain-specific and EF brain regions (Aim 2) in 7-8 yo children. After EF recruitment and connectivity have been established, behavioral correlates that influence EF connectivity to domain-specific regions will be examined in a larger group of children, over-sampled for reading and math difficulty (Aim 3), to facilitate a greater understanding of the underlying cognitive mechanisms of learning and how EF may vary by reading and math skill level. This proposal integrates behavioral and neuroimaging approaches, to fulfill the candidate’s short-term goals to distinguish the recruitment and connectivity of EF in reading and math for children and the behavioral correlates that influence EF brain activity and connectivity to understand development. These findings will support her long-term goals to use these complementary methodologies to develop effective interventions for struggling learners and to identify how the recruitment of EF may differ across development. The proposed training plan will provide skills necessary to have a successful, independent research career in academia by enhancing the candidate’s research program, while also expanding her research skills in four key areas: (1) a greater understanding of the underlying cognitive mechanisms of reading and math, (2) advanced computational and statistical approaches to neuroimaging data, (3) scholarly productivity in educational neuroscience, and (4) professional development. The candidate’s career and training plan will take place at Vanderbilt’s University (VU), a consistent recipient of funding from the National Institutes of Health. VU has a top-ranking Special Education Program with one of the few educational neuroscience programs and has substantial resources to provide support to the candidate during the K99 phase of the award.

NIH Research Projects · FY 2025 · 2024-09

Project Summary Osteoarthritis (OA), a leading cause of years lost to disability worldwide, is characterized by the breakdown of the collagen II-rich matrix of articular cartilage, infiltration of immune cells, and inflammation of joint tissues such as the synovium. Because no disease-modifying drugs exist to treat arthritis, surgery is the eventual result for patients with progressive OA. Though current biologic therapies for treating OA offer some clinical benefit, outcomes deteriorate over time due to the inability of these approaches to induce robust, sustained regeneration of cartilage and stabilization of joint tissues. Investigational cell engineering strategies have been developed to overcome the limitations of current regenerative medicine approaches, but these strategies fail to regulate cell functions based on reliable signatures of disease. Lack of such disease-dependent regulation of cell behaviors can lead to aberrant cell activities that negatively impact health or fail to mitigate disease. Here, we propose to leverage advanced cell design platforms to confine expression of transgenes to sites characterized by joint degeneration. Our approach builds on our use of a customized cell sense and response system in musculoskeletal bioengineering. This synthetic biology signaling system enables us to enlist cells as programmable agents that implement defined regenerative procedures when they encounter selected features of a microenvironment. Our prior studies have illustrated that exposed collagen II serves as a diagnostic hallmark of OA. This proposal capitalizes on our recent demonstration that an engineered synthetic receptor designed to detect collagen II selectively licenses mesenchymal stem cells to detect damaged cartilage and then upregulate expression transgenes known to promote cartilage synthesis and attenuate inflammatory signaling associated with OA. The overall goal of our work is to establish synthetic receptor-controlled, joint-resident cells as agents to coordinate cartilage repair and antagonize inflammation in the arthritic joint. This project will characterize the ability of our receptors to drive T cells and synoviocytes to mediate cartilage repair in an in vitro model of arthropathy (Aim 1) and will assess the ability of transplanted, synthetically programmed cells to detect and respond to cartilage degeneration in an in vivo model of post-traumatic OA (Aim 2). Finally, Aim 3 will establish feasibility of deploying this technology in the context of an off-the-shelf gene therapy capable of programming cells in situ to respond therapeutically to damaged cartilage.

NIH Research Projects · FY 2025 · 2024-09

Approximately 50% of adults in the United States have at least one chronic disease, and rates of burden vary greatly among affected individuals. Early diagnosis and intervention of chronic diseases are key features of precision medicine initiatives, which are further complicated by heterogeneity among both risk factors and genetic susceptibility. Despite the development of ancestry-informed genomic analyses, which can be applied to determine ancestry-driven genetic susceptibility for disease risk, there is a lack of heterogeneity in predictive ability effecting both recently admixed and non-admixed groups. Moreover, few genetic studies are positioned to examine the modifying effects of risk factors, which can result in inflated estimates of genetic effect leading to further inaccurate predictive ability. The utilization of ancestry-informed genomic analyses and the integration of ancestry-driven genomic discoveries in precision medicine is paramount for the accuracy and innovation in treating chronic disease. This proposal details the ways in which I, Ms. Kimberlyn Ellis, will fill these detrimental gaps through my doctoral and anticipated postdoctoral research. In Specific Aim 1 (The Dissertation Research Project), I will investigate the interactions between genetic variation, genetic ancestry, and known risk factors in the context of electronic health record data using asthma as a well-characterized and proof-of-principle chronic disease phenotype. In Specific Aim 2 (The Postdoctoral Research Direction), I will conduct a landscape analysis of current genomic-driven precision medicine initiatives, including ethical, legal, and social implications. After narrowing my focus to initiatives that lack accurate and precise predictive ability, I will develop and assess a list of priorities related to integrating ancestry-informed genomics into these studies. The proposed studies will greatly advance the field of genomics in two important ways. First, they will provide a rigorous framework for elucidating the poorly understood relationships between genetic ancestry, known risk factors, and chronic disease. Second, they will provide guidelines and recommendations for implementing ancestry-informed genomics in large-scale clinical settings, creating advancements in predictive ability for precision medicine initiatives. Moreover, the completion of these aims and funding from this award will be imperative to my ultimate goal of building an impactful researcher seeking to break down scientific silos and foster cross-sector collaboration towards comprehensive genomic efforts.

NIH Research Projects · FY 2024 · 2024-09

Alzheimer’s Disease (AD) is a progressive neurodegenerative disease and future treatments are likely to be most effective in early stages, prior to the onset of dementia. The first detectable pathology in AD is the accumulation of a 42 amino acid Aβ peptide (Aβ42) in extracellular plaques in the brain. This amyloid deposition, which is the characteristic feature of AD, occurs decades before clinical onset of dementia. The availability of biomarkers is crucial for early detection of, and monitoring of, the progression of AD. Cerebrospinal fluid (CSF) concentrations of Aβ42 in AD patients are lower than controls and correlate with the amount of plaque determined either by positron emission tomography or at autopsy. Blood assays for Aβ42 would clearly be preferable, but are more problematic. Currently a ratio of Aβ42 to Aβ40 is used. A significant problem with plasma Aβ42/40 measurement is that Aβ is also produced by extracerebral tissues that are not affected by AD. Biomarkers, such as phosphorylated tau peptides, have been employed, together with Aβ42/40 ratio for defining AD. What is urgently needed are better blood biomarkers of AD, in particular one that mirrors the state of amyloid in the brain. Our hypothesis is that measurement of the levels of a newly identified, i.e previously unreported, covalently crosslinked Aβ peptide dimer will provide this biomarker. Elucidation of the structure of this novel crosslinked Aβ dimer has recently been achieved in our laboratories, and its structure has been proven by independent synthesis. We were able to determine the structure of this crosslink as a result of an ongoing, well- established collaboration between our groups on age-related protein crosslinking. Importantly, this novel crosslink forms spontaneously, is abundant in brain, and covalent crosslinking of two adjacent Aβ peptides can occur only once fibrils are intimately aligned within amyloid in the brain. It is therefore amyloid-specific and cannot form in extracerebral tissues. Crucially, the Aβ dimer fraction from brain, has been shown to be neurotoxic in several bioassays. Under the same conditions, the Aβ monomer was quite inert. Therefore, unlike other currently used biomarkers, levels of blood Aβ dimer may reflect damage that is occurring in the brain of AD patients. Our ultimate aim is to make monoclonal antibodies to this crosslink to enable its specific detection. Manufacture of these monoclonal antibodies and development of an ELISA assay for use in potential bioassays, forms the major part of this NOSI proposal. A bioassay specific for a brain-derived neurotoxic form of Aβ would be a major advance in AD diagnosis.

NSF Awards · FY 2024 · 2024-09

Neurodiversity is a concept that acknowledges and embraces the natural variations in neurological traits, functions, and behaviors among individuals (i.e., ADHD, dyslexia). Autism is widely recognized as a form of neurodivergence with the prevalence of autistic people in the United States estimated at 1 in 36. Autistic people are significantly underrepresented and underutilized in the STEM workforce, especially in the category of Skilled Technical Workforce (STW). Autistic and neurotypical individuals often experience difficulties working together due to differences in how they interact with each other, which has unjustly limited employment opportunities for autistic people. This project proposes a fundamentally different approach that will help support and scaffold teamworking skills between autistic and neurotypical individuals. This will include employing a novel teaching approach called the Double Empathy paradigm--which situates the challenge of communication between neurodivergent and neurotypical individuals in the interaction, not in either individual—through a collaborative virtual reality technology tool embedded with artificial intelligence (AI), to support cross-neurotype teaching and learning. The AI-based embedded agent will provide real-time feedback to both neurotypes (autistic and neurotypical). This will help identify early signs of communication breakdowns and provide guidance to restore effective collaboration. The proposed research will be conducted in technical colleges with autistic and non-autistic young adults. This project will help support an inclusive society by developing tools and models that facilitate independence and employment for neurodivergent individuals, particularly those who are autistic. Creating conditions for leveraging their unique strengths can transform societal costs into significant value, especially in the vital domain of STW. The project findings are expected to be scalable and applicable to other neurodivergent groups, such as individuals with ADHD. This theory-driven project investigates the challenges of cross-neurotype communication, collaboration, and problem-solving, focusing on interactions between neurodivergent and neurotypical individuals. The project applies human-centered design methods to explore the proof-of-concept and feasibility of innovative learning technologies, aiming to improve communication and collaboration between neurodivergent and neurotypical youth. The proposed AI-embedded virtual reality program will track and foster cross-neurotype collaboration, problem-solving, and teamwork by: (1) collecting multimodal data such as speech, eye gaze, and physiology during collaborative tasks in a virtual environment; (2) interpreting this data using affective computing; (3) synthesizing feedback based on the Double Empathy paradigm; and (4) providing real-time feedback through an embedded intelligent agent. The convergent team comprises researchers in Computer Science, Engineering, Learning Science, Data Science, Organization Science, and Disability Studies. The project team will study the efficacy of the proposed intervention in enhancing learning outcomes, skill acquisition, and the overall experience of cross-neurotype learners in technical fields. The team will use quantitative methods (e.g., surveys, skill assessments) and qualitative methods (e.g., interviews) to analyze impacts on participant engagement, skill retention, and self-efficacy. This project is funded by the Research on Innovative Technologies for Enhanced Learning (RITEL) program that supports early-stage exploratory research in emerging technologies for teaching and learning. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2025 · 2024-09

PROJECT SUMMARY/ABSTRACT RNA interference (RNAi) using short interfering RNA (siRNA) is a promising strategy to block disease- causing targets that are difficult to selectively and/or potently block with conventional small molecule drugs. Five siRNA drugs are now in clinical use, all gaining FDA approval since 2018. The first siRNA drug was a lipid nanoparticle, but subsequent drugs are “carrier-free” molecular conjugates enabled by chemical modifications to the RNA that provide nuclease stability. Carrier-free technologies are of great interest due to manufacturing simplicity and reduced risk of carrier (cationic polymer or lipid) associated side effects and toxicities. siRNAs can be readily designed and optimized for hitting any gene in the body and, therefore, have tremendous therapeutic potential. However, all siRNA drugs currently approved by the FDA aim to silence gene expression in the liver, and no new siRNA drugs have been approved for treatment of diseases localized to or emanating from other sites in the body. We are optimizing siRNA conjugates for treatment of osteoarthritis (OA), a degenerative joint disease that is a leading cause of physical disability in the United States. Current OA treatments, such as steroids, reduce pain but can cause side effects and do not halt or slow progression of the disease. siRNA therapeutics offer the option to block the genetic underpinnings of the disease and have the potential to yield the first disease modifying osteoarthritis drugs (DMOADs). The proposed project aims build from our recent work developing siRNA molecules end-modified through a PEG linker with a diacyl lipid (siRNA-L2), which spontaneously forms a molecular complex with albumin (alb/siRNA-L2) in situ following intravenous injection. We have shown this albumin “hitchhiking” siRNA-L2 to be safe and to have a high level of accumulation and on-target gene silencing activity in injured joints. Cells residing in OA-afflicted joints produce inflammatory cytokines and matrix metalloproteinases (MMPs) that initiate and propagate the joint degenerative process. The overall goal of this proposal is to implement siRNA-L2 to systemically treat and block progression of PTOA and to build from promising data showing that silencing of MMP13 has therapeutic benefit in post-traumatic OA. Specifically, this project will (1) elucidate the mechanism of action of siRNA-L2 against MMP13 in OA, (2) test new chemical modifications for improving joint retention and activity of siRNA-L2, (3) test for efficacy of siRNA-L2 targeting MMP13 in a larger (non-rodent) animal model, and (4) establish the platform nature of siRNA-L2 against other gene targets associated with pathogenesis of OA. The investigative team for this interdisciplinary project spans RNA chemistry/therapeutics (Duvall), OA biology and single cell RNA sequencing (Maerz), and OA clinical care (Crofford). These successful scientists cover the areas of expertise required for the proposed work, assuring high probability of the project’s success.

NIH Research Projects · FY 2025 · 2024-09

SUMMARY/ABSTRACT Cytochrome P450 (P450) enzymes are involved in the oxidations of ~95% of chemicals, including many drugs, steroids, and chemical carcinogens. The practical application of P450 research to drug metabolism has been a notable highlight in the pharmaceutical industry in the past three decades. Many of the leaders in this field have trained in this laboratory. Variations in P450s are issues in drug-drug interactions, endocrine diseases, cancer, and other medical problems. Despite some success using directed evolution and protein engineering, there is still much room for improvement in the development of P450s as biocatalysts. In this proposal, I plan to address several important questions about human P450 enzymes, including both microsomal and mitochondrial P450s: Is the Compound I intermediate (FeO3+) the only oxidant involved in P450 reactions, including steroid C-C bond cleavages? What are the physiological roles of the remaining human P450 orphans (i.e., the P450s that do not presently have a clear function)? What is the physiological relevance of P450 27C1 in human skin—we know the reactions catalyzed by this enzyme but we do not know the function. What are the roles of other binding proteins (other than for retinoids) in P450 oxidations of lipophilic physiological compounds? What is the molecular basis of P450 17A1-cytochrome b5 interactions and is there a potential for developing drugs for prostate cancer? Techniques to be used include organic synthesis, spectroscopy, enzyme kinetics, mass spectrometry, proteomics, X-ray crystallography, and cell and molecular biology. Collectively the proposed experiments will provide useful information about the functions and mechanisms of several human P450s and have continued relevance in the fields of endocrinology and drug metabolism.

NIH Research Projects · FY 2024 · 2024-09

PROJECT SUMMARY/ABSTRACT Synapses are the fundamental signaling components of the nervous system and mediate trans-neuronal information transfer. Brain functions require the precise, stereotyped establishment of diverse synaptic connections into circuits during development, followed by the refinement and maintenance of these circuits throughout life. Information processing by synaptic circuits underlies the brain's ability to generate behavioral responses, and circuit alterations are hallmarks of neurological disorders. Despite the importance of synaptic circuit formation for understanding brain functions and neurological diseases, the fundamental cellular and molecular framework mediating these processes in the mammalian brain remain unknown. Emerging evidence suggests that trans-synaptic signaling by networks of cell adhesion molecules directs critical aspects of synaptic circuit assembly and function. Our previous studies found that the adhesion G-protein-coupled receptor (aGPCR) Latrophilins (Lphn) mediate the synaptic wiring specificity of the hippocampal CA1 region. aGPCRs exhibit the unusual dual function of trans-cellular adhesion and control of intracellular GPCR signal transduction cascades. Studies of aGPCRs provide an opportunity into understanding the mechanisms of circuit assembly and function. aGPCRs are the second-largest GPCR class containing 33 members in humans that are poorly understood. For example, while a significant fraction of FDA-approved drugs target well-studied GPCRs, no effective therapeutics exist presently for aGPCRs although they have been linked to a range of diseases, including cancer, ADHD, and autism. Many aGPCRs are highly expressed in the brain, but their biological functions and signal transduction mechanisms remain unclear. More generally, lack of mechanistic insights into brain circuit assembly is precluding a deeper understanding of behavioral neuroscience and the basis of neurological disorders. Our studies will interrogate the biological principles of mammalian central nervous system circuit assembly using a multidisciplinary combination of approaches. First, we will determine the biological functions and signaling mechanisms of the aGPCRs. These studies will provide insights into an understudied class of GPCR and reveal novel principles of mammalian central nervous system development. We will subsequently employ genome engineering combined with live imaging approaches to monitor the dynamics of synaptic connections forming in mammalian circuits down to the nanoscale level. Our studies will use these approaches to visualize neural circuit assembly in both aGPCR mouse models and human neurons derived from patients with neurological disorders. Furthermore, using a combination of molecular and genetic approaches, we will determine the molecular codes operating in distinct synaptic subtypes during in vivo synaptogenesis. Collectively, these studies will overcome several current obstacles in the field and illuminate fundamental principles of how the mammalian brain assembles via synaptic connectivity.

NIH Research Projects · FY 2025 · 2024-09

Project Summary We propose to further develop, refine, and validate our emerging free-solution assay (FSA) technology and our relatively new compensated Interferometric reader (CIR).1,2 The development of FSA-CIR addresses a significant void, a blind spot in cancer research because it represents the only label-free, solution-phase, ultra- sensitive, enzyme-free, technology compatible with essentially any matrix. Unlike existing tools, FSA-CIR has been shown to be useful for; a) mechanism of Action (MOA) studies on unadulterated/unmodified targets and probes with no relative mass sensitivity, b) full-length membrane protein interaction studies in native matrix, c) defining allosteric modulation and weak protein-protein interactions, d) accelerating quantitative assay development, e) potentially addressing biomarker discovery/validation bottleneck, f) performing quantitative interactions across the matrix spectrum on a single platform and g) enabling ex-vivo measurements to guide first-in-human dose determinations (FIHD) (see Pfizer letter). FSA-CIR is a paradigm shifting technology based on a novel molecular interaction transduction method with fluorescence-level sensitivity, and capabilities for targeting, probing, and assessing molecular and cellular features of cancer biology, as well as improving early detection and screening, clinical diagnosis. FSA is mix-and-read, agnostic to the molecular interaction pair and compatible with complex matrices, making it uniquely applicable in both the basic and clinical cancer research arenas. CIR represents a major advancement in interferometric sensing, due to an unprecedented level of sample-reference compensation CIR is operated without external thermal control, a unique feature for a refractive index (RI) sensor with <10-7 RIU sensitivity. The optical engine in CIR is unique, patented and quite simple, consisting of a diode laser, capillary tube, mirror and detector. When combining the interferometer with a droplet generator for sample introduction, CIR facilitates quantification of molecular interactions without relative mass dependence, at picomolar sensitivity and allows good sample throughput (50 serum sample-reference pairs run in quintuplet, [5 replicate droplet pairs], plus calibrations in a day. Feasibility of our assay methodology is demonstrated for mechanism-of-action (MOA) studies, quantification of drug target engagement as needed in theranostics and ultrasensitive, volume constrained, biomarker assay development, and target quantification. Data indicate FSA-CIR has the potential for widespread applicability and adoption throughout the scientific community and is mature enough to be an R-33 project. At project completion we aim to provide the scientific and medical community with a user-friendly platform technology for biochemical mechanism of action studies, to aid in improving cancer prognostics, and the ability to measure properties such as molecular and/or cellular mechanisms important in cancer.

NSF Awards · FY 2024 · 2024-09

This award supports research on understanding and predicting the evolution of the backward erosion piping (BEP) phenomenon in geotechnical flood protection infrastructure. BEP is a type of internal erosion mechanism, where soil in a permeable sand layer that resides underneath the cohesive foundation of river levees progressively erodes. BEP has been found to be the present in nearly one third of all recorded failures of water retaining structures. Moreover, flood risk is expected to increase across many parts of the United States as a result of climate change, causing the expected yearly flood damage to increase significantly. This research project will develop novel modeling and computational capabilities for the prediction of BEP, with the goal of providing a fundamental understanding of the interrelationships between soil characteristics, hydraulic conditions, infrastructure geometry and the evolution of erosion. The research team will also carry out educational and outreach activities in the Pennsylvania and Tennessee regions, to share results from the research with the wider public. A strong focus will be to use Augmented Reality-based tools to create novel learning activities to educate K-12, undergraduate students and the public on topics related to flood protection and hazard mitigation. The technical goal of this research is to mechanistically understand and characterize the relationship between hydraulic conditions in flood protection infrastructure systems and the time-dependent evolution of BEP. The research objectives to achieve the technical goal are: (1) the definition of a stochastic multiphase model of BEP evolution; (2) model-enabled discovery of fundamental erosion mechanics; and (3) characterization of the fundamental relationships between system properties, soil characteristics, and backward erosion potential. A stochastic multiphase computational model will be devised by leveraging and building on the Dual Random Lattice Modeling approach. The computational model will be exercised to gain mechanistic understanding of BEP through the idea of a numerical laboratory, where the model outcomes along with multiscale experimental evidence are used together to update the constitutive model form and the associated theoretical model that conceptualizes the constitutive form. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2025 · 2024-09

PROJECT SUMMARY Understanding individual differences in language comprehension and use in autism is a top priority of autism research, as acquisition of language early in life is consistently linked with long-term social, academic, and vocational outcomes in individuals on the autism spectrum. However, studying language of infants and young children who will later be diagnosed with autism is difficult due to the challenges of reliably diagnosing autism in the first 3 years of life, when expressive language develops rapidly. Studying infants who are known to be at increased familial likelihood for autism and language disorder (e.g., based on their status as younger siblings of at least one older autistic child) allows researchers to better understand what factors may predict expressive language in infants who are likely to go on to have autism and/or developmental language disorder. Recent work focused on this population has investigated what caregiver factors influence language development, as caregivers are infants’ primary communication partners and help to scaffold language development by providing linguistic input and facilitating contingent transactions. One such factor is caregiver stress, as caregivers of autistic children report experiencing high levels of stress. In previous work, PI Markfeld found preliminary support for a model whereby perceived, parenting-related stress was indirectly associated with expressive language in toddlerhood via caregiver linguistic input in the home environment in a sample of infants at increased likelihood for autism. The current project will extend the applicant’s prior work in multiple ways. Aim 1 will expand the characterization and measurement of caregiver stress by collecting a measure of stressful life experiences (i.e., objective stressors) in infants at increased familial likelihood for autism. Aim 2 will examine associations between perceived and objective caregiver stress, caregiver linguistic input, and child language outcomes later into childhood (i.e., at age 3 years) in infants at increased familial likelihood for autism. Aim 3 will assess whether this model of how caregiver stress influences child language outcomes may generalize to a larger sample of infants recruited from the general population. It is hypothesized that caregivers of infants at high likelihood for autism will report higher levels of perceived and objective stress relative to caregivers of infants at lower likelihood for autism, but that the conceptual model whereby caregiver stress influences child expressive language via caregiver linguistic input will hold for all caregivers and infants. The comprehensive training plan will advance PI Markfeld’s skills in measurement of caregiver stress and child language, characterization of autism and language disorders, and application of advanced approaches to statistical analyses. If the hypotheses are borne out, this work has the potential to pinpoint novel targets for early intervention that are intended to support optimal language outcomes for all infants. Improved understanding of the predictors and mechanisms by which infants learn language has the potential to guide future efforts in working with families to mitigate the long-term impacts of language learning difficulties.

NIH Research Projects · FY 2025 · 2024-09

PROJECT SUMMARY Zellweger spectrum disorders (ZSDs), which affect 1:50,000 individuals in the U.S., are characterized by dysfunction in any one of 13 peroxisomal biogenesis proteins (known as peroxins) and result in severe neurological phenotypes including seizures, developmental delay, and abnormal white matter growth in the brain. Life expectancy for patients rarely surpasses a few years. The peroxisomal biogenesis factor 11 beta (PEX11b), which is essential for peroxisomal fission, is among the peroxins mutated in ZSDs. However, the exact mechanisms by which peroxisomal morphology may contribute to disease pathophysiology remain unclear. This proposal aims to directly manipulate peroxisomal morphology during neurodevelopment by genetically deleting PEX11b and characterizing how PEX11b deficiency affects peroxisomal morphology, peroxisome-mediated metabolic functions, and early human neurogenesis. We aim to approach these questions by using PEX11b knockout (KO) human induced pluripotent stem cells (hiPSCs), which I have generated using CRISPR/Cas9. We will first assess the effects of PEX11b deficiency on peroxisomal morphology using super-resolution microscopy and rigorous, automated analysis of peroxisomal fission events, and peroxisomal length and volume from acquired images. To evaluate neurodevelopmental effects of knocking out PEX11b, we will evaluate self- renewal and multipotent differentiation potential in hiPSC-derived neural progenitor cells, as well as self-renewal of the neural progenitor pool and cortical layer formation in hiPSC-derived forebrain organoids. To assess the metabolic consequences of knocking out PEX11b, we will leverage metabolomics and imaging-mass spectrometry, among other cutting-edge metabolic profiling techniques, to evaluate whether downregulation of PEX11b alters cellular levels of long-chain, branched-chain, and very-long-chain-fatty acids. Successful completion of these aims would help establish the contributions of peroxisomal morphology during neurodevelopment. Additionally, it would help determine whether disruption of peroxisomal dynamics underlies ZSDs.

NIH Research Projects · FY 2025 · 2024-09

ABSTRACT Developmental stuttering is a common speech disorder characterized by prolongations, blocks, and repetitions of speech sounds. Studies of developmental stuttering within twin, family, and population isolates suggest a strong genetic influence on stuttering risk with heritability estimates ranging from 0.42 to 0.84. Population-wide studies suggest that stuttering genetic risk factors are complex and involve both familial and population-level variation. In the largest genome-wide association study (GWAS) of stuttering, we identified 57 unique genome- wide significant loci associated with self-reported stuttering risk. Despite these population and familial efforts, the functional role that genetic variation contributes to stuttering risk remains largely uncharacterized. The current work proposes to use extant self-report stuttering GWAS results and newly genotyped and sequenced whole- exome data to better understand the biological mechanisms contributing to stuttering risk. Aim 1 will explore the genetically regulated gene expression associated with self-reported stuttering by leveraging GWAS summary statistics in over 1.1 million cases and controls. We will perform sex- and ancestry-specific transcriptome-wide association analyses using Joint-Tissue Imputation, prioritizing brain and neuromuscular tissues. We will assess consistency and generalizability of the genetically regulated gene expression associated with self-reported stuttering in independent sex- and ancestry- specific analyses in two independent cohorts - the International Stuttering Project and the Adolescent Health study. To explore the role of rare functional variation, Aim 2 will pinpoint familial genetic effects of developmental stuttering. Using array and whole- exome sequenced data collected in over 200 families, we will perform a novel polygenic risk-adjusted multipoint linkage analysis approach, conduct transmission disequilibrium tests, apply a pedigree variant annotation analysis search tool (pVAAST), and meta-analyze rare and common gene-based results developed in Aim 1. Aim 3 will identify neural endophenotypes related to stuttering-associated genes. We will utilize a newly developed tool, NeuroimaGene, to assess the genetic relationship between stuttering associated genes from Aims 1, 2, and the literature with neural endophenotypes measured in more than 33,000 people in the UKBiobank. Results from Aim 3 will illuminate specific neural mechanisms contributing to stuttering risk via genetic mechanisms and will be compared to results from the literature on brain imaging in people who stutter. Together, these aims will characterize functional relationships contributing to stuttering risk, better inform our understanding of stuttering, as well as potentially inform clinical and therapeutic practices.

NIH Research Projects · FY 2025 · 2024-09

PROJECT SUMMARY Exosomes are a type of small extracellular vesicle (EV) secreted from all kinds of cells, derived from endosomes. They have many physiological and pathological functions, such as cell proliferation and differentiation, angiogenesis and wound healing, regulation of immunity, and cancer progression. They also play roles in maintaining tumor microenvironments and driving cancer metastasis through cargo delivery to recipient cells in paracrine and autocrine manners. The laboratory of Dr. Alissa Weaver (Unit Director) at Vanderbilt University School of Medicine studies the regulation of cancer cell migration and invasion by exosomes and the role of cancer cell exosomes in cancer aggressiveness and metastasis. The lab also carries out research on the biogenesis of RNA-containing exosomes and the development of imaging tools to track exosomes. The proposed studies for this R50 application of Dr. Bong Hwan Sung (Research Specialist) are related to two NCI-funded R01 grants: 1. Exosome secretion in breast cancer progression. This project tests the central hypothesis that adhesion molecules carried by cancer and fibroblast exosomes drive multiple steps of the metastatic cascade in breast cancer. 2. Regulation of extracellular vesicle biogenesis through cell adhesion. This project tests the hypothesis that the biogenesis of motility-promoting EVs in cancer is controlled by syntenin-dependent regulation of EV formation and cargo loading downstream of activated leukocyte cell adhesion molecule (ALCAM)-mediated adhesions. Dr. Sung has worked with Dr. Weaver for the past 15 years. As an expert in cell biology, EVs, and imaging techniques, Dr. Sung has set up state-of-the-art imaging techniques, and developed experimental and imaging tools and image analysis methods in her laboratory. This project will support those ongoing efforts.

NIH Research Projects · FY 2025 · 2024-09

PROJECT SUMMARY This work proposes to refine novel non-invasive magnetic resonance imaging (MRI) methods to quantify cerebral oxygen extraction and to apply these methods in persons with sickle cell anemia (SCA) to elucidate potential mechanisms for cerebral infarct development. SCA, caused by homozygous inheritance of mutant hemoglobin S (HbS), is the most severe and yet common form of sickle cell disease affecting approximately 1 in every 500 African Americans in the United States. The disease is characterized by the sickling of erythrocytes following deoxygenation of mutant HbS, which manifests in patients as chronic hemolytic anemia and possible vascular occlusion. More than half of individuals with SCA will have a silent cerebral infarct (SCI) by age 30 years; while largely asymptomatic at the time of injury, these SCIs can lead to progressive infarctions and cognitive deficits. Despite the high risk of infarction in these patients, few patients exhibit traditional risk factors for stroke such as macrovascular steno-occlusion and as such it has been difficult to develop biomarkers that can be used to triage patients for conservative versus more aggressive disease-modifying or curative therapies. Cerebral infarctions in persons with SCA are likely due to alternative vascular and metabolic changes at the tissue level secondary to the disease. It is well-established that cerebral blood flow (CBF) is elevated in SCA to compensate for reduced hemoglobin, but CBF is an incomplete predictor of ischemic risk by itself. Prior work in our lab has shown reduced capillary transit times in the presence of elevated CBF in individuals with SCA may lead to inefficient cerebral oxygen extraction at the capillary level. It is critical to accurately characterize these and possibly related changes in tissue physiology to establish functional biomarkers that can be used to triage patients with SCA to risk- appropriate treatments, or rather, to use these biomarkers as end-points in clinical trials. To address these needs, non-invasive imaging methods such as the asymmetric spin echo (ASE) MRI sequence have been developed to characterize cerebral oxygen extraction in humans. However, current methodological variants underestimate cerebral oxygen extraction metrics due to technical shortcomings of isolating extravascular water signal in the sequence. The goals of this proposal are (1) to refine and evaluate MRI methods to accurately quantify regional cerebral oxygen extraction and (2) to understand relationships between regional changes in oxygen extraction and blood transit times in adults with SCA before and after blood transfusions that modulate hemoglobin and flow velocities. Successful completion should provide new methods to monitor tissue health in SCA and to improve our understanding of how tissue subserves oxygen in the setting of anemia and in response to treatments.

NIH Research Projects · FY 2025 · 2024-09

PROJECT SUMMARY Immune checkpoint inhibitors (ICIs) enable anti-tumor immunity by blocking immunoregulatory receptor-ligand interactions (e.g., programmed cell death protein 1 [PD-1] and its ligand [PD-L1]). Despite their widespread success as an anti-cancer therapy, ICIs function poorly in patients with bone metastases, and bone loss and elevated fracture risk are reported in patients receiving ICI therapy. My preliminary data indicate that PD-1 global knockout or pharmacologic blockade decreases bone mass in both tumor naïve mice and mice with bone-metastatic disease (E0771 tumor cells). Furthermore, PD-1 blockade reduces bone strength compared to IgG control treatment in mice with bone metastases. These data are consistent with reports of bone loss and fractures in patients treated with ICIs. I have also found that osteoclast activity and CD8+ T cell populations capable of secreting pro-osteoclastogenic cytokines are elevated in the bone marrow after PD-1 blockade. I therefore hypothesize that the detrimental effects of PD-1 blockade on bone stem from CD8+ T cell expansion, which promotes osteoclast-induced bone destruction, and that tumor resistance to ICIs in the bone microenvironment stems from T cell dysfunction. I propose to (1) determine how immune cells influence PD-1 blockade-induced bone loss, and (2) investigate the mechanism behind T cell dysfunction and tumor resistance to ICIs in the bone microenvironment. In Aim 1 (F99 phase), I will use T cell depletion and adoptive transfer studies to investigate the role of bone marrow immune cells on PD-1 blockade-induced bone loss in tumor-inoculated mice. I will also treat tumor-inoculated mice with α-PD-1 in combination with bisphosphonates to assess prevention of bone loss. In both of these studies, I will assess the bone phenotype via microCT and biomechanical strength testing, and the tumor and immune phenotypes via flow cytometry and histology. In Aim 2 (K00 phase), I will utilize digital spatial profiling and scRNAseq technology to characterize T cell infiltration into bone metastases and identify key signaling pathways between tumor cells, immunoregulatory cells (myeloid derived suppressor cells, tumor associated macrophages T regulatory cells) and cytotoxic T cells, which are important in escape of bone metastatic tumor cells from the T cell anti-tumor response. I will use de- identified human breast cancer samples to validate my findings and elucidate the mechanism(s) by which bone metastases escape T cell surveillance (e.g., T cell suppression, T cell exhaustion, lack of T cell infiltration into the tumor microenvironment, etc.). With the current lack of understanding of the mechanism behind bone loss in patients treated with ICIs and tumor cell resistance to ICIs after bone dissemination, this proposal will help manage bone health in the millions of patients receiving ICIs each year and confirm mechanistically whether anti-resorptives reverse ICI-induced bone loss. Furthermore, I will uncover novel mechanisms of bone metastatic immune evasion that, when targeted, may increase efficacy of ICIs in bone metastatic patients.

NIH Research Projects · FY 2024 · 2024-09

Project Summary The importance of achieving stone-free status during endoscopic kidney stone surgery is emphasized by the high rate of repeat stone procedures due to residual fragments after index surgery. Specifically, residual stone fragments can lead to obstruction, pain, kidney injury, and recurrent infections. Currently, of the 100,000 patients who undergo an endoscopic kidney stone treatment each year, around 25,000 will require a repeat stone surgery within 20 months. Successful endoscopic stone surgery requires the surgeon to visualize the entire renal col- lecting system and locate all kidney stones during treatment. Challenges that lead to incomplete stone treatment involve inadequate stone visibility and difficulty navigating through the kidney. Complete kidney navigation relies on clinical experience and surgeons who have performed fewer cases have greater chances of recurrence. Our overall goal is to create an eye gaze based guidance system to complement the current standard of care where trainees only get verbal feedback. Gaze guidance has been shown to improve skill acquisition and retention in robot-assisted and laparoscopic surgery settings but has not been explored in the unconstrained environment of ureteroscopy. Our previous work in measuring eye gaze patterns shows similar differences in trainee vs. expert gaze behavior during kidney stone phantom procedures compared to those found in laparoscopic and robotic surgery. This suggested that using gaze training may similarly improve ureteroscopy skill acquisition. Successful eye tracking and eye gaze sharing in ureteroscopy require a tracking and registration system that does not constrain surgeons’ movements or head orientations. We propose head-mounted eye trackers that map gaze to the surgical monitor to flexibly track gaze as surgeons move around the operating room. We will evaluate whether the gaze sharing platform improves complete kidney visualization, which is required to identify stones that may not show up in pre-operative imaging, in phantoms and patients. The endpoint of this R21 will be a fully validated gaze-based training system for endoscopic stone surgery and the necessary experimental data to power a large-scale, multi-center clinical trial. As our training system is solely composed of software running on augmented reality devices, all existing endoscopic and laparoscopic surgical procedures could in principle immediately benefit from the results of this project. In this way, we believe the suc- cess of our project will facilitate improved training procedures and mitigate repeat interventions or complications, benefiting patients, surgeons, and society.

NIH Research Projects · FY 2024 · 2024-09

PROJECT SUMMARY Aging is a complex process characterized by many hallmarks, such as DNA instability, epigenetic changes, and loss of protein homeostasis. Cellular rejuvenation, which aims to restore cells to a youthful state, offers hope to counteract aging and its associated diseases. Recent advances in epigenetic reprogramming using Yamanaka factors (a set of four transcription factors) have rejuvenated aged cells to youthful states and extended lifespan in mice. However, the clinical use of Yamanaka factors is limited due to their tumorigenic risk and full reprogramming potential. Therefore, it is important to find new rejuvenating transcription factors that are safer and more potent than the Yamanaka factors. The Li lab has recently developed a systematic approach and identified ~30 potential rejuvenation transcription factors. They have identified ~30 transcription factors that can restore youthful gene expression patterns in aged human fibroblasts in vitro. Critically, they also validated a few top hits with cellular and molecular phenotyping of aging hallmarks. However, the underlying mechanisms by which these transcription factors/chromatin modifiers rejuvenate aged cells, and the ability of these transcription factors to rejuvenate other types of aged cells (such as post-mitotic cells) are unknown. To better prepare me for such research, I propose to continue my training in cell/molecular biology by investigating how BRWD3 regulates DNA replication and epigenetic modifications (F99 Aims). This will not only enhance my comprehensive skill set for mechanistic studies, but also deepen my understanding and investigative strategies for chromatin-associated proteins, which are central to my proposed F00 aging research. During the K00 phase, I will leverage my molecular research expertise and the Li lab's system-level approaches to advance our understanding of cellular rejuvenation. I propose to dissect the mechanism of a top rejuvenation candidate and identify its key targets responsible for rejuvenation (K00 Aim 2.1). I will also use the induced neurons with the system-level approaches developed by the Li lab to explore the rejuvenation potential of the top 30 transcription factors in aged neurons (post-mitotic). Collectively, these experiments will not only deepen our understanding of the rejuvenation mechanism, but also shed light on rejuvenation approaches for overlooked post-mitotic cells, leading to the discovery of safer and more universal rejuvenation solutions for both mitotic and post-mitotic cells.

NIH Research Projects · FY 2025 · 2024-09

PROJECT SUMMARY/ABSTRACT Research has shown that the security of a child's attachment to their primary caregiver is crucial to their social relationships and overall well-being. Attachment security is developed through contingent and responsive interactions between the child and caregiver, with physical proximity playing a vital role in building trust. Despite the importance of real-world caregiver–child interactions, previous research has largely focused on laboratory-assessed caregiver quality. To address this gap, we have developed a wearable device called TotTag, which can dynamically and unobtrusively measure real-time physical proximity between device wearers. TotTags are worn in vests by children and in waistbands by caregivers to assess patterns of close contact in children's everyday lives. In this NIH exploratory/developmental research grant, we plan to recruit 100 families with a 12-month-old child from diverse racial, ethnic, and socioeconomic backgrounds. During a home visit, we will assess caregiver sensitivity with up to two caregivers per child. Each caregiver and the infant will then wear TotTags from the child's wake time to bedtime (~12 hours) to assess time in close proximity and the number of caregiver–child "check-ins" (i.e., periods of close contact between periods of separation). Finally, we will conduct the Strange Situation Procedure to assess attachment security with each available caregiver. Aim 1 will explore aspects of caregiver–child proximity in relation to attachment security. Aim 2 will examine the potential additive and interactive contributions of caregiver sensitivity and caregiver– child proximity in relation to attachment security. By obtaining sensitivity and proximity data at the dyad level (e.g., child with mother; child with father) within a family, we aim to gain insight into the specific aspects of each caregiver–child relationship associated with attachment security. Furthermore, this rich intensive longitudinal data of proximity patterns will be made available to allow for exploration of other relevant questions of interest (e.g., associations with family structure; weekend vs. weekday patterns). In addition, we will obtain information regarding the fidelity and acceptability of ecological assessments in families with infants in anticipation of a larger program of research examining the longitudinal development of attachment starting in early infancy. This cross-sectional study, using innovative new technology coupled with home-based caregiver sensitivity assessments and gold-standard laboratory assessments of attachment, will provide an unprecedented picture of infants' daily experiences with their caregivers. Findings from this study will aid in setting the foundation for future work focused on fostering healthy development through secure attachment relationships.